In performing laproscopic surgery, an incision is made in a patient by a trocar to admit a cannula which serves as a conduit for the introduction of selected surgical instruments into a body cavity. During the surgical procedure, several cannulas may be directed into a patient at spaced locations to facilitate simultaneous use of a number of instruments. The body cavity in which the operation is performed is filled with a gas to expand the surrounding tissue to create a suitably sized operating space.
In the operating procedure, there are several major concerns. First, it is important to confine the gas used to expand the cavity in which the operation is to be performed. Deflation of the body cavity could result in interruption of a surgical procedure and/or injury to the patient.
It is important to maintain the cannula to be positively positioned on the body tissue through which it passes.
It is also important that the cannula be permitted to be reoriented with respect to the body cavity to maximize the working range for each instrument.
It is desirable to avoid traumatizing the skin surrounding the cannula so that recovery from the surgery is expedited.
Unfortunately, the above objectives are in conflict. In laproscopic surgery, the laparoscope is constantly moved, in and out, and side to side, to follow the procedure. During movements of the laparoscope, exudate accumulates in the cannula causing more drag and thus increasing the potential of pulling the cannula out of the patient. If the cannula is pulled out of the patient, the abdominal cavity will deflate and cause a delay while the insufflation pressure is reestablished. The trocar has to be reinserted, to reposition the cannula, causing additional trauma to the placement site.
By securing the cannula to the patient the risk of accidentally removing the cannula is reduced. However, there is additional trauma associated with prior art devices that have been used to secure the cannula. There is also a greatly reduced ability to reorient the cannula within the incision with such prior art devices.
There are a number of prior art patents disclosing devices utilized to solve the above noted problems. U.S. Pat. No. 5,002,557 (Hasson) discloses the use of a balloon or membrane that is attached to the base of a cannula. When the cannula is inserted into a patient, the membrane or balloon is inflated so as to increase the surface area of the base beyond that of the original insertion. This device adds additional complexity to a cannula that is discarded after each operation and thus increases the cost of the operation.
U.S Pat. No. 4,593,681 (Soni) discloses the use of a stabilizing plastic sheath that has a hole therein to accept an endoscope. This sheath has a locking mechanism to hold the endoscope in place. This device significantly reduces the ability of a surgeon to reorient an endoscope within an incision.
In a similar fashion, U.S. Pat. No. 2,350,775 discloses a cannula holder that positively locks a cannula in a particular position by a frame that is attached to the cannula.
U.S. Pat. No. 3,817,251 (Hasson) discloses an adjustable cone shaped sleeve for blocking the incision gap. The cannula is held in place by a pair of hooks that receive sutures attached to the patient. The use of sutures does aid in the positioning of the cannula but adds to the traumatizing of the surrounding tissue.
U.S. Pat. No. 3,253,594 (Matthews) discloses the use of an inflatable balloon in combination with a disk for holding a cannula in place. The balloon is inserted into the patient through an incision and then inflated to come into contact with the inside surface of the body cavity. The disk is attached to the balloon on the exterior of the patient's body. The disk has threads which engage a cap that is used for tightening the disk down upon the body. Thus, the balloon and disk combination are designed to create a frictional grip on the skin of the patient adjacent to the incision. This gripping tends to cause traumatizing to the skin.
Several patents disclose various ways to secure catheters to a patient. These patents include 4,324,236 (Gordon et al.); 4,985,018 (Smith); 4,737,143 (Russell); 4,669,458 (Abraham et al) and 3,670,727 (Reiterman). Theses devices would not function properly for holding a cannula since a cannula must have the ability to be reoriented in or out and side to side of the incision. The above devices are designed to secure a catheter to a patient so as to prevent the catheter from moving.